/*
 * Copyright (c) 2017, ARM Limited and Contributors. All rights reserved.
 *
 * SPDX-License-Identifier: BSD-3-Clause
 */

/*
 * Driver for GIC600-specific features. This driver only overrides APIs that are
 * different to those generic ones in GICv3 driver.
 *
 * GIC600 supports independently power-gating redistributor interface.
 */

#include <arch_helpers.h>
#include <assert.h>
#include <gicv3.h>

#include "gicv3_private.h"

/* GIC600-specific register offsets */
#define GICR_PWRR        0x24

/* GICR_PWRR fields */
#define PWRR_RDPD_SHIFT        0
#define PWRR_RDGPD_SHIFT    2
#define PWRR_RDGPO_SHIFT    3

#define PWRR_RDGPD        (1 << PWRR_RDGPD_SHIFT)
#define PWRR_RDGPO        (1 << PWRR_RDGPO_SHIFT)

/* Values to write to GICR_PWRR register to power redistributor */
#define PWRR_ON            (0 << PWRR_RDPD_SHIFT)
#define PWRR_OFF        (1 << PWRR_RDPD_SHIFT)

/* Generic GICv3 resources */
extern const gicv3_driver_data_t *gicv3_driver_data;

/* GIC600-specific accessor functions */
static void gicr_write_pwrr(uintptr_t base, unsigned int val)
{
       mmio_write_32(base + GICR_PWRR, val);
}

static uint32_t gicr_read_pwrr(uintptr_t base)
{
       return mmio_read_32(base + GICR_PWRR);
}

static int gicr_group_powering_down(uint32_t pwrr)
{
    /*
     * Whether the redistributor group power down operation is in transit:
     * i.e. it's intending to, but not finished yet.
     */
    return ((pwrr & PWRR_RDGPD) && !(pwrr & PWRR_RDGPO));
}

static void gic600_pwr_on(uintptr_t base)
{
    /* Power on redistributor */
    gicr_write_pwrr(base, PWRR_ON);

    /* Wait until the power on state is reflected */
    while (gicr_read_pwrr(base) & PWRR_RDGPO)
        ;
}

static void gic600_pwr_off(uintptr_t base)
{
    /* Power off redistributor */
    gicr_write_pwrr(base, PWRR_OFF);

    /*
     * If this is the last man, turning this redistributor frame off will
     * result in the group itself being powered off. In that case, wait as
     * long as it's in transition, or has aborted the transition altogether
     * for any reason.
     */
    if (gicr_read_pwrr(base) & PWRR_RDGPD) {
        while (gicr_group_powering_down(gicr_read_pwrr(base)))
            ;
    }
}

/*
 * Power off GIC600 redistributor
 */
void gicv3_rdistif_off(unsigned int proc_num)
{
    uintptr_t gicr_base;

    assert(gicv3_driver_data);
    assert(proc_num < gicv3_driver_data->rdistif_num);
    assert(gicv3_driver_data->rdistif_base_addrs);

    gicr_base = gicv3_driver_data->rdistif_base_addrs[proc_num];
    assert(gicr_base);

    /* Attempt to power redistributor off */
    gic600_pwr_off(gicr_base);
}

/*
 * Power on GIC600 redistributor
 */
void gicv3_rdistif_on(unsigned int proc_num)
{
    uintptr_t gicr_base;

    assert(gicv3_driver_data);
    assert(proc_num < gicv3_driver_data->rdistif_num);
    assert(gicv3_driver_data->rdistif_base_addrs);

    gicr_base = gicv3_driver_data->rdistif_base_addrs[proc_num];
    assert(gicr_base);

    /* Power redistributor on */
    gic600_pwr_on(gicr_base);
}
